Parameter

Description

AFMEANS calculates and prints tables of predicted means classified by treatment factors from an ANOVA analysis. It uses the same method as ANOVA itself, but with the extension that the term defined by the full list of factors need not have been included in the analysis. So, for example, you can obtain an A × B table of means, even if the model contained only the A and B main effects. Alternatively, in a more realistic scenario, you may have significant A.B and B.C interactions, but no A.B.C interaction. You might then still want to present an A × B × C table means, even though you might not want to include an A.B.C interaction.

The factors classifying the table of means are specified by the CLASSIFY parameter. By default the means are formed for the most recent ANOVA, but you can use the SAVE option to supply the save structure from an earlier analysis.

Printed output is controlled by settings of the PRINT option:

means

means,

ese

effective standard errors of the means,

sed

standard errors for differences between the means,

sedsummary

summary of the standard errors for differences between the means,

dfmeans

degrees of freedom for the standard errors of differences between means,

lsd

least significant differences between the means, and

lsdsummary

summary of the least significant differences between the means.

The default is to print means and a summary of the standard errors of differences. Note: if all the differences between means have the same standard error of difference, a summary is printed for the settings sed and lsd, instead of the full symmetric matrix of values. The LSDLEVEL option specifies the significance level (%) to use in the calculation of least significant differences (default 5%). The EQFACTORS option allows you to specify factors within the tables of means whose levels are assumed to be equal for the two means, when calculating effective standard errors.

The MEANS, SED, ESE, LSD and DFMEANS options allow the results to be saved in appropriate Genstat data structures.